Suzuki Grand Vitara JB416 / JB420. Manual — part 73

1A-241 Engine General Information and Diagnosis:

Troubleshooting

NOTE

• Before performed troubleshooting, be sure to read the “Precautions of ECM Circuit Inspection”.
• When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the

special tool to ECM and/or the ECM connectors referring to “Inspection of ECM and Its Circuits”.

Step

Action

Yes

No

1

Fuel injector check for operating sound
1) Using sound scope, check each injector for operating

sound at engine cranking.

Do all 4 injector make operating sound?

Fuel injectors circuit is
in good condition.

Go to Step 2.

2

Fuel injector resistance check
1) Disconnect connectors from fuel injectors with ignition

switch turned OFF.

2) Check for proper connection to fuel injector at each

terminals.

3) If OK, check all 4 fuel injectors for resistance referring to

“Fuel Injector On-Vehicle Inspection in Section 1G”.

Are all injectors in good condition?

Go to Step 3.

Faulty fuel injector.

3

Fuel injector insulation resistance check
1) Check that there is insulation between each fuel injector

terminal and engine ground.

Is there insulation?

Go to Step 4.

Faulty fuel injector.

4

Fuel injector power supply check
1) Measure voltage between each “BLU/BLK” wire terminal

of fuel injector connector and engine ground with ignition
switch turned ON.

Is voltage 10 – 14 V?

Go to Step 5.

“BLU/BLK” wire is open
or shorted to ground
circuit.
If it is in good condition,
go to “ECM Power and
Ground Circuit Check”.

5

Wire circuit check
1) Turn OFF ignition switch.
2) Disconnect connectors from ECM.
3) Measure resistance between each “PNK”, “PNK/BLK”,

“PNK/GRN”, “PNK/BLU” wire terminal of fuel injector
connector and vehicle body ground.

Is resistance infinity?

Go to Step 6.

“PNK”, “PNK/BLK”,
“PNK/GRN” and/or
“PNK/BLU” wire(s) are
shorted to ground.

6

Wire circuit check
1) Measure voltage between each “PNK”, “PNK/BLK”,

“PNK/GRN”, “PNK/BLU” wire terminal of fuel injector
connector and vehicle body ground with ignition switch
turned ON.

Is voltage 0 V?

Go to Step 7.

“PNK”, “PNK/BLK”,
“PNK/GRN” and/or
“PNK/BLU” wire(s) are
shorted to power supply
circuit.

7

Fuel injector drive signal check
1) Connect connectors to each fuel injector and ECM with

ignition switch turned OFF.

2) Turn ON ignition switch.
3) Measure voltage between each “C37-1”, “C37-2”, “C37-

16”, “C37-17” terminal of ECM connector and vehicle
body ground.

Is voltage 10 – 14 V?

Check fuel injector
referring to “Fuel
Injector Inspection in
Section 1G”.
If check result is
satisfactory, substitute a
known-good ECM and
recheck.

“PNK”, “PNK/BLK”,
“PNK/GRN” and/or
“PNK/BLU” wire(s) are
open circuit.

Engine General Information and Diagnosis: 1A-242

Fuel Pump and Its Circuit Check

S5JB0A1104066

Wiring Diagram

E23-1

E23-60

E23-15

BLU

BLU/BLK

BLK/RED

BLK/RED

BLU/BLK

E23-29

BLK/WHT

WHT/GRN

BLK/WHT

BLK/WHT

PNK

BLK

WHT/GRN

BLK/YEL

7

6

4

3

2

5

E23

C37

3

4

18

19

5

6

7

10

11

17

20

47

46

49

50

51

21

22

52

16

25

9

24

14
29

55

57

54 53

59

60

58

2

26

27

28

15
30

56

48

32

31

34

35

36

37

40

42

39 38

44

45

43

41

33

1

12

13

23

8

3

4

18

19

5

6

7

10

11

17

20

47

46

49

50

51

21

22

52

16

25

9

24

14
29

55

57

54 53

59

60

58

2

26

27

28

15
30

56

48

32

31

34

35

36

37

40

42

39 38

44

45

43

41

33

1

12

13

23

8

BLK/RED

1

E23-16

BLU/BLK

BLU/BLK

C37-15

C37-29
C37-48

BLK/ORN

C37-58

C37-30 BLK/ORN

BLK/YEL
BLK/YEL
BLK/YEL

8

9

I5JB0A110102-01

1. Fuse box No.2

4. Fuel pump relay

7. Ignition switch

2. Main relay

5. Fuel pump

8. “FI” fuse

3. ECM

6. “IG COIL” fuse

9. “IGN” fuse

1A-243 Engine General Information and Diagnosis:

Troubleshooting

NOTE

• Before performed troubleshooting, be sure to read the “Precautions of ECM Circuit Inspection”.
• When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the

special tool to ECM and/or the ECM connectors referring to “Inspection of ECM and Its Circuits”.

Step

Action

Yes

No

1

Fuel pump control system check for operation

Is fuel pump heard to operate 2 sec. after ignition switch is
turned ON?

Fuel pump circuit is in
good condition.

Go to Step 2.

2

Fuel pump relay power supply check
1) Disconnect fuel pump relay from fuse box No.2 with

ignition switch turned OFF.

2) Check for proper connection to fuel pump relay at each

terminal.

3) If OK, turn ON ignition switch, measure voltage between

“BLK/WHT” wire terminal of fuel pump relay connector
and engine ground.

Is voltage 10 – 14 V?

Go to Step 3.

“BLK/WHT” wire is open
or shorted to ground
circuit.

3

Fuel pump relay power supply check
1) Turn ON ignition switch, measure voltage between “BLU/

BLK” wire terminal of fuel pump relay connector and
engine ground.

Is voltage 10 – 14 V?

Go to Step 4.

“BLU/BLK” wire is open
circuit.

4

Fuel pump relay check
1) Check fuel pump relay referring to “Control Relay

Inspection in Section 1C”.

Is relay in good condition?

Go to Step 5.

Faulty relay.

5

Fuel pump relay drive signal check
1) Connect fuel pump relay to fuse box No.2.
2) Connect voltmeter between “E23-15” terminal of ECM

connector and vehicle body ground.

3) Measure voltage 2 second after ignition switch is turned

ON.

Is voltage 10 – 14 V?

Go to Step 6.

“WHT/GRN” wire is
open circuit or shorted
to ground circuit.

I2RH01110132-01

Engine General Information and Diagnosis: 1A-244

6

Fuel pump relay drive signal check
1) Measure voltage within 2 second after ignition switch is

turned ON.

Is voltage 0 – 1 V?

Go to Step 7.

Substitute a known-
good ECM and recheck.

7

Wire circuit check
1) Turn OFF ignition switch.
2) Detach fuel tank referring to “Fuel Tank Removal and

Installation in Section 1G”.

3) Disconnect connector from fuel pump.
4) Measure resistance between “PNK” wire terminal of fuel

pump connector and vehicle body ground.

Is resistance infinity?

Go to Step 8.

“PNK” wire is shorted to
ground.

8

Fuel pump circuit check
1) Connect service wire between “E23-15” terminal of ECM

connector and vehicle body ground.

2) Turn ON ignition switch, measure voltage between

“PNK” terminal at fuel pump connector and vehicle body
ground.

Is voltage 10 – 14 V?

Go to Step 9.

“PNK” wire is open
circuit.

9

Fuel pump circuit check
1) Turn OFF ignition switch.
2) Measure resistance between “BLK” wire terminal at fuel

pump connector and vehicle body ground.

Is resistance less than 5

Ω

?

Faulty fuel pump.

“BLK” wire is open
circuit.

Step

Action

Yes

No